1. Field of the Invention
The present invention relates to a composite part for an electronic musical instrument which is composed of a plurality of members joined together by a rivet.
2. Description of the Related Art
A composite part directed by the present invention may be used, for example, as a hammer in a keyboard-based musical instrument such as an electronic piano. The hammer is adapted to pivot in association with a corresponding key depressed on a keyboard to provide a touch feeling similar to that of an acoustic piano. The hammer is typically composed of a hammer body made of synthetic resin or the like, a weight attached to the hammer body for controlling key touch, and so on. Conventionally, the weight is formed of a lead-made cylinder having a predetermined weight, which is inserted into an attaching hole formed at a predetermined position of the hammer body, caulked, and laterally swelled to be attached to the hammer body. Since such a hammer is composed of the hammer body and the weight made of different materials from each other, i.e., synthetic resin and lead, the two components are preferably disassembled, when the keyboard musical instrument is disposed, from a view point of reusing resources. However, since the hammer has the weight fully embedded in the attaching hole of the hammer body, the disassembly of the hammer body and the weight presents extreme difficulties. In addition, the lead itself comprising the weight is deleterious to the environment.
For this reason, as a recent hammer for replacement with the conventional lead-based weight, there is known a hammer which uses a weight made of an iron plate or the like and formed with a rivet inserting hole, and a hammer body also formed with a rivet inserting hole, such that a rivet is inserted through the two rivet inserting holes and the leading end portion of the rivet is caulked to attach the weight to the hammer body. With this hammer, since the head of the rivet and the caulked leading end portion protrude from the hammer body, the hammer can be readily disassembled by cutting the head or the leading end portion of the rivet with an electric drill.
The foregoing hammer, however, has the head and the leading end portion, the surfaces of which are planar or curved, so that, a drill, when in contact with the head or the leading end portion for disassembling the hammer, is susceptible to slippage, and therefore is difficult in positioning the center thereof, resulting in inefficient disassembling works.